Nguyễn et al. (2020) — Autogenous Healing of High-Strength ECC
Citation
Huy Hoàng Nguyễn, Jeong-Il Choi, Se-Eon Park, Sang Lyul Cha, Jungwon Huh, Bang Yeon Lee (2020). Autogenous healing of high strength engineered cementitious composites (ECC) using calcium-containing binders. Construction and Building Materials, 265, 120857.
- DOI:
10.1016/j.conbuildmat.2020.120857 - Atlas layer: supporting
- Related Victor Li book chapter: Chapter 8: Self-Healing and Durability of ECC (also Chapter 10)
- Source PDF:
primary_data/nguyen-2020-autogenous-healing-of-high-strength.pdfIJP05620E_Autogenous healing OGS_CBM.pdf` - Extracted text:
secondary_data/full_texts/nguyen-2020-autogenous-healing-of-high-strength_full_text.mdsecondary_data/full_texts/IJP05620E_Autogenous healing OGS_CBM_full_text.md` - Source note:
secondary_data/source_notes/nguyen-2020-autogenous-healing-of-high-strength_source_note.mdsecondary_data/source_notes/IJP05620E_Autogenous healing OGS_CBM_source_note.md`
Why this paper matters
Investigates autogenous self-healing in high-strength ECC ($f_{cu} > 94\text{ MPa}$, $\epsilon_u > 4.5\text{ \%}$) made with calcium-containing binders (PC, CEA, GGBS), demonstrating that Portland cement-rich ECC (M-C, $f_{cu} = 103.6\text{ MPa}$) achieves 100 % crack closure for cracks $<50\ \mu\text{m}$ ($90.0\text{ \%}$ overall healing rate), 44.8 % resonant frequency recovery, and a post-healing tensile strength surge to 10.30 MPa (+28.8 %) via synergistic C-S-H and $\text{CaCO}_3$ formation.
Main contribution
- High-Strength Ductile ECC Formulation: Developed 100 MPa high-strength ECCs with $>4.5\text{ \%}$ tensile strain capacity: M-C ($f_{cu} = 103.6\text{ MPa}$, $\epsilon_u = 5.25\text{ \%}$, $\sigma_{tu} = 8.00\text{ MPa}$), M-E ($f_{cu} = 94.1\text{ MPa}$, $\epsilon_u = 4.75\text{ \%}$), and M-S ($f_{cu} = 95.5\text{ MPa}$, $\epsilon_u = 4.68\text{ \%}$).
- Image Processing Crack Area Healing Rate: Proved $d_h = 100\text{ \%}$ complete closure for cracks $<50\ \mu\text{m}$ and $90.0\text{ \%}$ overall closure in M-C.
- Post-Healing Tensile Strength Surge (10.30 MPa): Reloading healed M-C specimens produced a 28.8 % increase in tensile strength ($8.00 \rightarrow 10.30\text{ MPa}$) with new microcracks forming in virgin matrix.
Evidence summary
- 28-Day Mechanical Properties:
M-C: $f_{cu} = 103.63\text{ MPa}$, $\sigma_{tu} = 8.00\text{ MPa}$, $\epsilon_u = 5.25\text{ \%}$, 53.5 cracks ($w_{avg} = 82.9\ \mu\text{m}$, spacing 1.57 mm) (Tables 5–7, Pages 4–5).M-E: $f_{cu} = 94.14\text{ MPa}$, $\sigma_{tu} = 8.07\text{ MPa}$, $\epsilon_u = 4.75\text{ \%}$, 37.8 cracks ($w_{avg} = 99.9\ \mu\text{m}$, spacing 2.20 mm).M-S: $f_{cu} = 95.47\text{ MPa}$, $\sigma_{tu} = 8.24\text{ MPa}$, $\epsilon_u = 4.68\text{ \%}$, 20.3 cracks ($w_{avg} = 155.0\ \mu\text{m}$, spacing 4.23 mm).- Crack Healing Rate ($d_h$): M-C = 100 % for $w < 50\ \mu\text{m}$ (90.0 % overall) vs M-E = 60.4 % vs M-S = 41.5 % (Fig. 6, Page 7).
- Stiffness Recovery (RF): M-C reached 44.8 % normalized RF after 36 days (Fig. 10, Page 9).
- Reloading Tensile Strength: M-C reached $\sigma_{tu} = 10.30\text{ MPa}$ (+28.8 %) (Table 9, Page 10).
Linked Atlas nodes
02_concepts/self_healing_mechanisms.md04_material_systems/high_strength_ecc.md05_experiments/crack_width_distribution.md02_concepts/strain_hardening_criteria.md05_experiments/direct_tensile_test.md
Relationship to Victor Li book
- Primary book anchor remains Victor Li (2019), Engineered Cementitious Composites (ECC).
- Directly supports Chapter 8 (Self-Healing ECC) and Chapter 10 (High-Strength ECC) by establishing quantitative healing thresholds ($50\ \mu\text{m}$) and mechanical reloading recovery for 100 MPa ECC.
Claim-evidence rows to add
| Atlas node | Claim | Evidence summary | Page/Figure/Table | Status |
|---|---|---|---|---|
04_material_systems/high_strength_ecc.md |
Portland cement-rich high strength ECC achieves 103.6 MPa compressive strength and 5.25 % direct tensile strain capacity | Direct tension tests verified $f_{cu} = 103.63\text{ MPa}$, $\sigma_{tu} = 8.00\text{ MPa}$, and $\epsilon_u = 5.25\text{ \%}$ | Page 120857:1 & 5 / Table 5 & Table 6 | verified_from_pdf |
02_concepts/self_healing_mechanisms.md |
M-C composite achieves 100 % crack closure for cracks $<50\ \mu\text{m}$ (90.0 % overall healing rate) and 44.8 % resonant frequency recovery | Digital image processing confirmed $d_h = 100\text{ \%}$ for $w < 50\ \mu\text{m}$ and 44.8 % RF recovery | Page 120857:5 & 8 / Fig. 6 & Fig. 10 | verified_from_pdf |
02_concepts/self_healing_mechanisms.md |
Reloading self-healed M-C composite increases tensile strength to 10.30 MPa (+28.8 %) with new microcrack formation | Uniaxial tension reloading at 36 days measured $\sigma_{tu} = 10.30\text{ MPa}$ with new microcracking | Page 120857:8 & 11 / Table 9 / Fig. 7 & 12 | verified_from_pdf |
Verification status
- PDF preserved: yes (in
primary_data/IJP05620E_Autogenous healing OGS_CBM.pdf) - Text extracted: yes (PyMuPDF, 16 pages)
- DOI verified: yes (
10.1016/j.conbuildmat.2020.120857) - Page/figure/table verified: yes (all checked in PDF text)
- Claim-evidence matrix ready: yes
Cautions
- Excessive GGBS without activator (80 % in M-S) depletes $\text{Ca(OH)}_2$, leading to wider cracks ($155\ \mu\text{m}$) and poor healing.